Strange, I've just done Namtars Lair with a Hoarder Tinker using nothing but Pissorff and Crystal ball (and whatever sinergizes) for the most part (Alchemist Pact and a few points of mana from the gods, B2P, nothing from the subdungeons). Only used fireballs for the phys res form. What seems to be the problem? Because that's most likely the easiest method for doing that place, I'm not sure what to recommend otherwise.
If you're going Warmonger than a berserker, most likely, with Dragonshield, and you need to make sure you go down with cleansing, but getting your phys resistance up to snuff might prove to be a pain, and it's way more complicated than PoS...
Pos is just - farm 100 Binlor Piety (damage boons optional, I ussually get them) - move to a different god - make sure there's something to slap a boss into that's not a wall - loot the shops for anything spellcastery or that gives base damage, but emphasize refills (in other words save money for the CB) - get to an arbitrary level between 2 and 5 (often just 1, one kill away from 2) - spam pissorf untill either the boss or whever you're slapping him into drops otherwise ignore any numbers on the screen, just watch the bars to see if they're epmty - if the bars are empty kill stuff untill you ding (use healing potions if you have them to get heatlh to do so) - keep doing it untill all the bossess are dead - if you killed something and don't have anything to slap the boss into, use pissorff or whatever to move him further (often easier if you move stuff in advance). Refill bars with potions and CB and Schadenfraude and whatever the god supplies when you feel like it, but rather go for dings if possible. Make sure you're not slapping a phys res guy into stuff but the other way around. That's it, any dungeon, any monsters, any class/race, numbers highly irrelevant, debuffs highly irrelevant, gods highly irellevant, gameplay always the same and more strightforward than even the Rat King was. Orcs and Wizards just somewhat better at it than most others and not by much really for some.
Only tricky bit most of the time is if the boss spawins somewhere where it's difficult to hit him into something, but it's very rare that there's nothing to slam him into at all. Otherwise you gotta play it not like you're playing a DD run, but like you're a serviceman for a bot that's coded to always win a DD run whatever the run is 100% guranteed and you're just there to pull levers when the little bars run out of mana and health to refill them. Or like you're watching a you tube vid that keeps pausing itself every so often and you have to click on something to keep it chugging but what you have to click on changes place on the screen.